My Nikor 105 is certainly multicoated from the looks of it and my Rodagon 150 is just as certainly single coated. My 50mm Companon-S could be multicoated from it's looks but I am not positive. I just have to wonder how much difference it makes when printing B&W. I have several single coated 4x5 lenses that compete quite well with my multicoated lenses.
I am assuming you feel that multicoating would help resolve flare problems in enlarging. In Ctein's enlarger lens test there doesn't seem to be any correlation between coated and uncoated in his flare testing. I am assuming Nikors to be coated and Rodagons not. His testing results and his conclusion is that flare is not a problem with the newer 6 element lenses, and significantly he doesn't mention coatings.
I obviously agree with Paul's statement as I have one from each manufacturer simply because I found each one used at a good price.